Adjustable chair frame



FIG. 1 is a side elevation of an adjustable chair frame showing my new design;

FIG. 2 is an end elevation as seen from the left of FIG. 1;

FIG. 3 is an end elevation as seen from the right of FIG. 1;

FIG. 4 is a top plan view looking downwardly onto FIG. 1; and

FIG. 5 is a bottom plan view looking upwardly to FIG. 1. 

The ornamental design for an adjustable chair frame, as shown. 